title: A life-course perspective on physical functioning in women.
abstract: OBJECTIVE
  To validate Kalache & Kickbusch's model: namely, that functional capacity peaks in early adulthood, then declines at a rate dependent on fitness level until a "disability threshold" is reached.
  
  
  METHODS
  Data came from the Australian Longitudinal Study on Women's Health, which followed three cohorts from 1996 to 2011: a young, a mid-aged and an older cohort (born in 1973-78, 1946-51 and 1921-26, respectively). The Short Form (36) Health Survey was used to measure physical functioning (score 1-100). The disability threshold was the mean physical functioning score in older women requiring assistance with daily activities (62.8). The relationship between age and physical functioning was modelled using spline regression for the entire sample, and by baseline physical functioning quintile and physical activity level.
  
  
  RESULTS
  PHYSICAL DECLINE QUICKENED WITH AGE: 0.05 annual units (95% confidence interval, CI: -0.13 to 0.22) at ages 18-23 years (i.e. no decline); -2.43 (95% CI: -2.64 to -2.23) at ages 82-90 years. Decline was faster in quintiles with lower baseline physical functioning in the younger and mid-age cohorts and in quintiles with higher baseline physical functioning in the older cohort. The disability threshold was reached at a mean age of 79 years, but the range was 45-88 years, depending on baseline physical functioning and physical activity.
  
  
  CONCLUSIONS
  Age and physical decline are not linearly related, as traditionally believed; decline accelerates with age. However, baseline physical functioning, but not physical activity, influences the rate of decline.
authors.affiliation: Schools of Human Movement Studies and Population Health, The University of Queensland, Bldg 26b Blair Drive, St Lucia, Queensland 4072, Australia .
authors.forename: Geeske
authors.initials: G
authors.lastname: Peeters
authors.forename: Annette J
authors.initials: AJ
authors.lastname: Dobson
authors.forename: Dorly J H
authors.initials: DJ
authors.lastname: Deeg
authors.forename: Wendy J
authors.initials: WJ
authors.lastname: Brown
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D008962:Models, Theoretical; D011795:Surveys and Questionnaires / Q000592:standards*; D055815:Young Adult